/*******************************************************************************
 * Copyright 2006, 2017 Jerry Huxtable, Martin Davis
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * This file was semi-automatically converted from the public-domain USGS PROJ source.
 */
package org.locationtech.proj4j.proj;

import org.locationtech.proj4j.ProjCoordinate;

public class CrasterProjection extends Projection {

	private final static double XM = 0.97720502380583984317;
	private final static double RXM = 1.02332670794648848847;
	private final static double YM = 3.06998012383946546542;
	private final static double RYM = 0.32573500793527994772;
	private final static double THIRD = 0.333333333333333333;

	public ProjCoordinate project(double lplam, double lpphi, ProjCoordinate out) {
		lpphi *= THIRD;
		out.x = XM * lplam * (2. * Math.cos(lpphi + lpphi) - 1.);
		out.y = YM * Math.sin(lpphi);
		return out;
	}

	public ProjCoordinate projectInverse(double xyx, double xyy, ProjCoordinate out) {
		out.y = 3. * Math.asin(xyy * RYM);
		out.x = xyx * RXM / (2. * Math.cos((out.y + out.y) * THIRD) - 1);
		return out;
	}

	/**
	 * Returns true if this projection is equal area
	 */
	public boolean isEqualArea() {
		return true;
	}

	public boolean hasInverse() {
		return true;
	}

	public String toString() {
		return "Craster Parabolic (Putnins P4)";
	}

}
